1. Field of the Invention
The present invention relates to a waterproofing apparatus for waterproofing an end of an electrical cable whose conductor (cores) is coated with insulating material around its outer periphery, such as an earthing electrical cable provided in the engine compartment of an automobile, and to a waterproofing method of an electrical cable end. In particular, the present invention relates to an electrical cable end waterproofing apparatus that, in an electrical cable that has a terminal having a ring shaped contact installed on its end for example, reliably prevents water from entering the terminal, and to an electrical cable end waterproofing method.
2. Description of the Related Art
In general, an earth cable is connected to an earthing point (such as an automobile body) in a state in which a connecting terminal, which is crimped on its end, is exposed. Therefore, if water is splashed on the earth cable, the water enters the inside of the electrical cable from the part of the terminal that is crimped to the electrical cable (crimped part). If the water moves along the inside of the sheathing material, and enters the inside of the internal equipment to which the earth cable is connected, there is concern about negative effects such as disrupting the normal operation of the internal equipment. Therefore, it is necessary to apply treatment (waterproof treatment) to the crimped part of the earth cable in order to prevent water from entering the inside of the electrical cable.
Heretofore, as a method of applying waterproof treatment to an electrical cable such as an earth cable or the like, a method is disclosed in which resin is molded so that the crimped part of the electrical cable is covered. In this method, not only does the molding require time and a large scale apparatus, but also the shape of the resin molded part becomes large, so that there is a problem in that it is difficult to perform wiring arrangement.
Therefore, a waterproof treatment method (for example, refer to Japanese Unexamined Patent Application, First Publication No. 2004-355851) in which, by dispensing a liquid waterproofing agent to one end of an earth cable, and suctioning the air inside the sheathing material of the earth cable from the other end to reduce the pressure, the liquid waterproofing agent applied to the electrical cable end permeates the inside of the sheathing material, and a waterproofing apparatus (for example, refer to Japanese Unexamined Patent Application, First Publication No. 2006-202676) that is used in this waterproofing method, have been proposed.
However, in the methods disclosed in Japanese Unexamined Patent Application, First Publication No. 2004-355851 and Japanese Unexamined Patent Application, First Publication No. 2006-202676, in the case where waterproofing is applied to a long electrical cable or an electrical cable with a large diameter, in order to reduce the pressure of the inside of the sheathing material sufficiently, the apparatus for suctioning the air inside of the sheathing material from the other end becomes large, and in addition, it takes a long time to permeate a liquid waterproofing agent into the inside of the sheathing material sufficiently. As a result, there is a problem in that the treatment cost is high.
The present invention has been made in view of the above circumstances, and has an object of providing a waterproofing apparatus for an electrical cable end that can efficiently perform waterproofing of the end of an electrical cable, such as one for earthing or the like, regardless of the length or the diameter (wire diameter) of the electrical cable, and waterproofing method for an electrical cable end in which it is used.